Where can I find a description of the protocol for transferring messages from the POS terminal to the video surveillance system?

Question

Payment terminals

Recently, Synology's Surveillance Station has the ability to display transaction records conducted by POS terminals on video. Actually, I wanted to know in what format these messages are transmitted, how they can be emulated, what software is available for this.
Ideally, I would like to generate these messages with an arduino, and transmit them to the monitoring station. Who can throw literature on this subject. As I understand it, there is some certain standard by which everyone works. How to create a query for a search on this topic in Google?

Answer 1

You should first read where exactly Synology receives data from, what terminals it works with, etc. And then look for how to emulate the work of a specific terminal.